Time control for stokers



May 2, 1933. L. TEEPLE 1,906,435

TIME CONTROL FOR STOKERS Filed March 26, 1930 3 Sheets-Sheet 1 L. R.TEEPLE':

M y 1933- R. TEEPLE TIME CONTROL FOR STOKERS 1930 3 Sheets-Sheet Filed March 26 L R .TEEPLE flTTERN E/ Patented May 2, 1933 W PATENT OFFICE LAWRENCE R. TEEPLE, OF PORTLAND, OREGON 7 TIME CONTROL FOR STOKERS 1 Application filed March 26, 1930. Serial No. 438,979.

This invention relates generally to coal burning stokers, and particularly to a time controlled switch therefor.

The main object of this invention is the construction of a control switch whereb a stoker can be intermittently operated uring periods of time in which it is not being operated by other controls.v

- The second object is to construct a special form of switching echanism for providing such intermittent o eration.

The third object is to construct a time control mechanism having a variable speed control-therefor. W

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawings, in which: p

' Figure 1 is a somewhat diagrammatic section through the device showing its relation to associated elements. 2

Figure 2 is a front-elevation of the time -dial. w 7 Figure 3 is a section taken along the line 3 e in Fig. 1; v

Figure 4 is' a perspective view of the switching mechanism.

taken along the line -Figure 6 is a fragmentary elevation' of the speed-cdntrol lever and its mounting.

- Figure 7 is a diagrammatic detail of the time switch actuating-mechanism.,

Similar numbers of reference refer to similar parts throughout theseveral views.

Referring in detail to the drawings in order to illustrate this invention there is shown a stoker l0 above which is shown a floor 1 1 of a room which is heated by a radiator 12 from the boiler13 which is supplied with a temperature or pressure actuated switch 14 such as'are in common use.

Heat is generated in the boiler 13 or its pressure is increased by the operation of the stoker 10 under the control of a day and night thermostat Within the room 15.

The thermostat is preferably of the double element type in which the sensitive element 16 is operated during the night period'and 5 the element 17 during the day period. The day period is indicated-on the dial 18 by means of a light portion 19 and the night period is indicated by means ,of the darkened portion 20. Two sets of numbers 21 5 ranging from 1 to 12 represent the hours of the day and are opposite the holes 22 between which are the half hour holes 23.

The dial 18 is secured on the shaft 24 which journals in the sleeve 25 which in to turn journals in the sleeve 26 across the plates 27 and 28. The shaft 24' also journals in the hub 29 of a gear 30 which is fric--. tionally' driven from the shaft 24 by means of the spring '31. The hub 29 journals in the'plate 32. On the opposite side of the plate 32 and secured to the shaft 24 is a collar33 against which the spring 31 reacts.

On the sleeve 26 is mounted a lon arm. 34 having a laterally turned end 35. ,5n the sleeve 25 is mounted a short arm 36 provided with the laterally turned end 37. On the outer end of the sleeve 26 is secured an arm 38 provided with an inturned point 39 which is positioned in front of the darkened area 20 representing a night period of operation.

I The arm 38is provided with a pin 40 which normally occupies one of the holes 22 or 23 and is withdrawn therefrom for re-settingpurposes merely by pushing the point 39 toward the dial 18. U

On the "sleeve 25 is secured an arm 41 whose inturned end42 forms a pointer which is positioned adjacent to the light area 19 representing a daylight period of operation, i

The arm 41 is positioned with relation to the dial 18 by means of a pin 43. 1 On the plate 32 is mounted a rocker arm 44 which carries a roller 45 adapted to engage the points 35 and 37 as they pass. The

varm 44 has a contact arm 46 secured thereto which, in Fig. l, is shown in engagement with the contact point 47 which is connected by means of a wire' 48 to the night thermostat 16. The Contact point 49 is connected by means of a wire 50 to the day thermostat 17. The contact arm 46 is urged toward either extreme position by means of a spring 51.

Mounted between the plates 28 and 32 is a time train consisting of a small electric motor 52 and the gears 53, the last of which is mounted on the shaft 54 provided with the pinion 55 which is in constant mesh with the gear 30. On the end of the shaft 54 is mounted a friction disk 56. Parallel with the face of the disk 56 is mounted a shaft 57 which journals in the standards 58 on the slidable base 59 which can be moved parallel to the axis of the shaft 57 by means of a lever 60 which is pivoted on the plate 27.. A spring 61 is employed to provide a desirable amount'of friction between the base 59 and the plate 27 and also to hold the friction wheel 62, which is secured on the shaft 57, toward the disk 56. On the shaft 57 are, also secured the three cams 63, 64 and 65 made of some material which is a noncon'ductor of electricity.

Extending from the base 59 is a bracket 66 on which is mounted an insulated holder 67 which carries at one end a pair of contact arms 68 and 69 which are spaced from each other. v The arm 68 rests upon the cam 63. At the middle of the holder 67 is a.

single contact arm 70 which rests on the cam 64. The arm 70 has secured thereto a transversely extending arm 71 which extends between the arms 68 and 69. At the opposite end of the holder 67 are three contact arms 72, 73 and 74. The arm 73 rests upon the cam 65. The arm 72 normally contacts with the arm 73 but this contact-is broken and a new contact made between the arms 73 and 74 when the arm 73 is raised by the cam 65. The arm 68 is normally in contact with the arm 71 but, under the action of the cam 64, a contact is made between the arms 69 and ;l which is of course connected to the arm In the drawings there is also shown a stoker motor 75 by means of which the stoker 10 is operated. Its lead wires 76 connect with the terminal blocks '77 and 78 of arelay switch 7 9which also includes a transformer 80 and an actuating switch 81 for the time switching mechanism. The actuating switch 81 consists primarily of a shaft 82 which is operated by a small electric motor 83 through a reduction gearing (not shown). On the shaft 82 is mounted a fiber cam 84 on the side of which is a metal contact disk 85 having a cut-away portion 86 formed therein. Against the side of the disk 85 ride the brushes 87, 88 and 89 of which the brush ,88 is always in contact with the disk 85 and the remaining brushes are alternately disconnected therefrom by means of the cut-away portion 86.

The function of the cam 84 is to intermittently close the circuit of the .stoker motor 75 by means of the contact arms 90, one of which is joined to the terminal block 77 and the other to the terminal block 91 which is joined to the line wire 92 and, by means of the wire 93, to the primary circuit of the transformer 80 which also connects with the terminal block 94. The terminal block 94 connects with the line wire 95 and to the terminal block 78 by means of a wire 96 which 'forms the circuit for the motor 75. The secondary circuit 97 of the transformer 80 connects with the motor 83 from whence it connects with the brush 89 to the terminal block 98 from whence it passes through the pressure controlled switch 99 within the member 14 to the contact posts 100 of the night and day thermostats 16 and 17 which come into contact with their respective sensitive elements when the temperature or pressure within the boiler 13 falls below a predetermined minimum.

The contact posts 101 are joined by the circuit 102 to the member 14 from which it passes to the terminal block 103 and connects with the brush 87, which is also connected with the secondary coil of the transformer 80. The brush 88 is joined by the wire 104 to the terminal block 105 from whence it passes through the member 14 to the contact arm 70. The circuit 97 is joined by means of a wire 106 to the contact arm 74. The circuit 102 is joined by means of the wire 107 to the contact arm 72. The contact arm 73 is joined by the wire 108 to the contact arm 69. The contact arm 68 is joined by means of the wire 109 to the rocker arm 44. The motor 52 is joined by means of the lead wires 110 to the line wires 92 and 95. The operation of the device is as follows:

Assuming. that the dial 18 has been posi-.

tioned to correspond with the hours of the day and it is desired to have the temperature of the room 15 from fifty to fifty-five degrees between the hours of four-thirty in the afternoon and one-thirty in the morning and it is desired to have the remainder of the twenty-four hours held between seventyfive and eighty degrees, the first step is to adjust the thermostats 16 and 17 for these temperatures. The second step is to rotate the dial 18' untilnumber 6 of the darkened portion 20 is opposite the pointer 112 which happens to be the actual time of the day at which this operation is being commence In other words---it is merely setting the dial to the right time of day.

If the switch 111 is closed manually current at once flows to the motor 52, the 0peration of which causes the dial. 18 to revolve and, according to the time of daythat is whether it is day or nightwithin the limits above mentioned through the operation of the arms 34 and 36, to rock the 19 ly making a contact.

arm 44 moving the arm 46 in one direction or the other.

ln'Fig. 1 the night thermostat 16 is shown in an operative position, although not exact- The motor 52 runs continuously as long as the switch 111 is closed and therefore the shaft 57 is operated continuously at a speed which is regulated by the lever 60. The motor 83, however, is thermostatically controlled and operates when the. temperature of the room 15 falls below a predetermined minimum until the brush 87 drops into the cut-away portion 86 at which time the cam 84 closes the stoker motor circuit. The motor 83 ceases to operate until the maximum room temperature is attained when themotor 83 is again operated by its thermostat until the cam has made a half revolution, at which time the motor 83 again stops, due to the fact that the brush 89 is in the cut-away portion 86.

The net result of the mechanism thus described is the production of a simple and durable time contacting mechanism whereby a stoker motor can be periodically and successively cut in and out for the purpose of maintaining avfire in a stoker when not otherwise operated, but the result aimed at especially in this application is the production of a device of this character in which it is easily possible to vary the length of the time intervals. (as shown in the drawings), This is accomplished by a mere shifting ofthe lever 60.

It will be appreciated that in place of the friction elements 56 and 62 that a suitable ratio of gears may be substituted without departing from the spirit of the invention.

The purpose of introducing this variable ratio in the time interval contacting mechanism is to better adapt the stoker to a wide range of installation requirements as occasioned by stack, draft, type of boiler, kind of coal burned and other factors familiar to those versed in the art.

Attention is drawn to a co-pending application. of Thomas H. Banfield, Serial Number 273,707, now patent '#1,778,3 l9, issued Oct. 14, 1930 over which this device is an improvement.

The function of the periodical time controlled actuating mechanism for the stoker motor is to cause the motor to be operated when the heat stored at the furnace falls below a predetermined point, regardless of the temperature requirements at the point of delivery. In other words, under the normal functioning of a dual control a normal temperature at either the furnace or in the room will cause a stoppage in the generation shall not take place while the furnace l have therefore temperature is normal. made it possible to insure against the fire becoming extinguished without causing an undesirable situation, such as the operation of the stoker by the time switching mechanism when the furnace temperature was already at the desired height which, in the case of a warm air furnace, might cause injury to the furnace, or with water or steam heating systems, cause a blowing ofi of the boiler.

1 claim:

1. A control for stokers having in combination day and night-thermostats each of which makes a contact at opposite ends of its temperature range, a pressure controlled circuit closing device mounted on a boiler, an underfeed stoker for supplying heat to said boiler, a motor for said stoker, a stoker motor relay switch, a motor for operating said relay switch under the control of said thermostats and pressure controlled circuit closing device, said relay switch operating motor under the control of a thermostat moving said relay switch to a closed position during minimum temperature or pressure conditions and to an open position during maximum temperature or pressure conditions, and a variable period time interval contacting mechanism continuously operated for the purpose of periodically operating said stoker motor only whenv same is not being operated in response to said thermostats or pressure controlled circuit closing device. 0

2. A time contacting device including day and night controls having in combination spaced supporting frame members, a time dial rotatably mounted on said frame members, a time train for driving said dial, a friction drive between said train and dial, a pair of indicators for said dial having separately operable switch throwing arms attached thereto, a switch operated by said arms for alternately actuating said day and night controls, a slidable base mounted on one of said frames, a cam shaft mounted on said base having a plurality of cams thereon, contact arms associated with said cams, a friction wheel secured on said cam shaft, a friction disk driven by said time train, and a lever for slidably positioning said base whereby said friction wheel may be moved along the diameter of said friction disk.

3. A time interval contacting device having in combination spaced supporting frame members, a time dial rotatably mounted on said frame members, a time train for frictionally driving said dial, a pair of indi cators for said dial having separately operable switch-throwing arms, a switch operated by said arms for alternately rendering operative day and night controls, a cam shaft mounted on said base having a plurality of cams thereon, contact arms associated with said cams, a Variable speed drive between said shaft and said time train, and means for regulating the action of said variable speed drive. I

' LAWRENCE R. TEEPLE. 

